projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| cc749e07 BJ |
1 | /* @(#)sleep.c 4.1 (Berkeley) %G% */ |
| 2 | #include <signal.h> | |
| 3 | #include <setjmp.h> | |
| 4 | ||
| 5 | static jmp_buf jmp; | |
| 6 | ||
| 7 | sleep(n) | |
| 8 | unsigned n; | |
| 9 | { | |
| 10 | int sleepx(); | |
| 11 | unsigned altime; | |
| 12 | int (*alsig)() = SIG_DFL; | |
| 13 | ||
| 14 | if (n==0) | |
| 15 | return; | |
| 16 | altime = alarm(1000); /* time to maneuver */ | |
| 17 | if (setjmp(jmp)) { | |
| 18 | signal(SIGALRM, alsig); | |
| 19 | alarm(altime); | |
| 20 | return; | |
| 21 | } | |
| 22 | if (altime) { | |
| 23 | if (altime > n) | |
| 24 | altime -= n; | |
| 25 | else { | |
| 26 | n = altime; | |
| 27 | altime = 1; | |
| 28 | } | |
| 29 | } | |
| 30 | alsig = signal(SIGALRM, sleepx); | |
| 31 | alarm(n); | |
| 32 | for(;;) | |
| 33 | pause(); | |
| 34 | /*NOTREACHED*/ | |
| 35 | } | |
| 36 | ||
| 37 | static | |
| 38 | sleepx() | |
| 39 | { | |
| 40 | longjmp(jmp, 1); | |
| 41 | } |